This invention is of important beneficial effect to the environment and relates primarily to apparatus for the prevention of hydrocarbon spillage at fuel dispensers of the type generally utilized at service stations, fuel depots and the like. It also has utility for the prevention of spillage at other types of equipment requiring periodic maintenance.
While the exact number of fuel dispensing stations serving the public in this country may not be known, it is known that it is upwards of two hundred thousand. Typically, each such station has multiple dispensers, and it is not uncommon to find six, ten, or even many more dispensers at each such station. The total number of such dispensers in this country exceeds two and one-half million. Each such dispenser has at least one filter that must periodically be replaced.
Most if not all such dispensers will have at least a water/fuel filter in close proximity to the outlet for dispensing such fuel. Such filters are typically horizontal, and typically have a capacity of approximately a quart or so of filtered fluid. Such filtered fluids are not pure, however, but are themselves normally contaminated by hazardous materials such as benzene, toulene and the like. Not only is the approximate volume of such filters inevitably spilled each time such filters are removed, but still more product, from the line upstream of such filters to the nearest check valve, is lost as well. In sum, the spillage from each change of filter may total from approximately one to two quarts.
While the total amount of spillage from the removal of any one filter may seem small, the effect is not innocuous. As but one example, gasoline does not degrade in the soil, but remains potent almost indefinitely. Most soils are of types that permit hydrocarbons to leach downward to underground water reservoirs, the pollution of which is an ever-increasing problem. So severe has the problem become in this country that in many localities any spillage greater than two fluid ounces requires formal notification to the proper authorities and initiation of formal decontamination procedures.
Spillage of one to two quarts per filter change per dispenser times an average of twelve such filters per station results in a total spillage of three to six gallons per station. If each station must change its filters even once every quarter, then the average station would be spilling on the order of 12 to 24 gallons of hazardous fluids, annually, just from such filter changes alone.
Those skilled in the art appreciate that such spills do not occur onto the concrete aprons surrounding the individual dispensing stations but directly onto the earth below such stations, and, thus, readily infiltrate the water table which in many localities may be but a very few feet below the surface. Those skilled in the art also appreciate the enormous investment that has been made in the dispensing apparatus now in use, and that replacement of such in any reasonably brief time period would be prohibitively expensive. There has thus existed for a long time an industry-wide need for moderately-priced apparatus to prevent such spillage which can be applied to existing equipment without the need for expensive re-design or expensive retrofitting. The present invention fulfills that long-standing need. In addition, should the present invention be widely adapted, then several million gallons of hydrocarbons presently polluting our nation's aquifers, annually, will have been eliminated.